added injection of markerb in Gemfile

lib/generators/devise/views_generator.rb

@@ -77,6 +77,26 @@ module Devise
       def target_path
         "app/views/#{scope || :devise}/mailer"
       end
+
+      def inject_makerb_content
+        if gemfile_exists?
+          append_file gemfile_path, gemfile_content
+        else
+          create_file gemfile_path, gemfile_content
+        end
+      end
+
+      def gemfile_path
+        @gemfile_path ||= File.join("Gemfile")
+      end
+
+      def gemfile_exists?
+        File.exists?(File.join(destination_root, gemfile_path))
+      end
+
+      def gemfile_content
+        'gem "markerb"'
+      end
     end
 
     class ViewsGenerator < Rails::Generators::Base

test/generators/views_generator_test.rb

@@ -33,6 +33,17 @@ class ViewsGeneratorTest < Rails::Generators::TestCase
     assert_files nil, :mail_template_engine => "markerb"
   end
 
+  test "Assert Gemfile got gem markerb injected" do
+    File.open(File.join(destination_root, "Gemfile"), 'w') {|f| f.write("gem 'rails'") }
+    run_generator %w(--markerb)
+    assert_file "Gemfile", /gem \"markerb\"/
+  end
+
+  test "Assert Gemfile got created with markerb if no gemfile" do
+    run_generator %w(--markerb)
+    assert_file "Gemfile", /gem \"markerb\"/
+  end
+
   def assert_files(scope = nil, options={})
     scope = "devise" if scope.nil?
     default_template = "html.erb"